1. Technical Field
The present invention relates to a sound collecting device, an acoustic communication system and a computer-readable storage medium, and in particular, to a sound collecting device, an acoustic communication system and a computer-readable storage medium that can form directivity by delaying and synthesizing respective acoustic signals obtained by collecting sound by plural sound-collecting microphones.
2. Related Art
Adaptive beamforming is known as a technique of estimating a direction in which there exists a sound source (hereinafter called “target sound source”), that outputs a sound that is a target, by a microphone array structured such that plural microphones are arrayed in a predetermined pattern, and forms the direction (hereinafter called “orientation direction”) of the directivity of the microphone array with respect to that direction. The technique disclosed in Japanese Patent Application Laid-Open (JP-A) No. 2007-13400 is known as an example of this technique.
In the technique disclosed in JP-A No. 2007-13400, by carrying out plural different filtering processings on respective acoustic signals obtained by collecting sound by respective microphones structuring a microphone array, acoustic signals relating to plural sound collecting areas are generated from the respective plural microphones. The acoustic signals, that are generated and obtained and relate to the plural sound collecting areas, are synthesized among the plural microphones for each sound collecting area. The acoustic signal having the highest signal level is selected from among the acoustic signals per sound collecting area that were obtained by the synthesizing. It is considered that the target sound source exists in the sound collecting area corresponding to the selected acoustic signal, and the microphone array forms an orientation direction with respect to the direction of that sound collecting area.